Aspects of the invention can relate to a projector that projects an image with the use of a liquid crystal display panel or any other type of light modulation device.
As an illumination device for a liquid crystal display panel incorporated into a projector in the related art, a type in which a light-source light from a white light source is separated into lights of three colors and relay lenses are disposed in illumination optical paths for two colors, so that efficiency for utilization of illumination of respective colors is improved by compensating for a difference of optical path lengths with respect to the remaining one color can be used. See, for example, JP-A-1-243014.